diff --git a/python/requirements/rllib/requirements_rllib.txt b/python/requirements/rllib/requirements_rllib.txt
index 5c21e9ea6084..5e04d5b09f24 100644
--- a/python/requirements/rllib/requirements_rllib.txt
+++ b/python/requirements/rllib/requirements_rllib.txt
@@ -20,7 +20,7 @@ gym[atari]==0.18.3
 kaggle_environments==1.7.11
 # Unity3D testing
 mlagents==0.26.0
-mlagents_envs==0.26.0
+mlagents_envs==0.28.0
 # For tests on PettingZoo's multi-agent envs.
 pettingzoo==1.11.0
 pymunk==6.0.0